Why Twitter is limited to 140 characters , twitter has its own answer. 140 Character service given life to some URL shorteners and ended the road to others where there is no business with link shortening . Symantec released a video to tell how worst clicking on malicious shortened links will affect your PC.

There is always security issue involved in clicking shortened links because user doesn’t know where the link pointing to. The loop hole of this had been using to their advantage by some malware authors to spread malware to twitter users through shortened links. If any user clicks on those links malware will be installed to their PCs.

Bit.ly is the default URL shortener for twitter and it does alert if shortened link from bit.ly points to malicious sites. Then what about shortened links from other services like tinyurl and others? does they alert? may be not. Luckily there are plug-ins available to see original URL of link before opening in browsers like Firefox and IE. I will cover them in upcoming posts . [Thanks to TechCrunch]